2 * Copyright (c) 2021-2022 Juniper Networks
4 * This software was developed by Mitchell Horne <mhorne@FreeBSD.org>
5 * under sponsorship from Juniper Networks and Klara Systems.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/param.h>
30 #include <sys/systm.h>
32 #include <sys/caprights.h>
34 #include <sys/eventhandler.h>
35 #include <sys/fcntl.h>
37 #include <sys/kerneldump.h>
38 #include <sys/limits.h>
39 #include <sys/malloc.h>
40 #include <sys/namei.h>
44 #include <sys/sysctl.h>
45 #include <sys/vnode.h>
47 #include <machine/pcb.h>
48 #include <machine/vmparam.h>
50 static dumper_start_t vnode_dumper_start;
51 static dumper_t vnode_dump;
52 static dumper_hdr_t vnode_write_headers;
54 static struct sx livedump_sx;
55 SX_SYSINIT(livedump, &livedump_sx, "Livedump sx");
58 * Invoke a live minidump on the system.
61 livedump_start(int fd, int flags, uint8_t compression)
63 #if MINIDUMP_PAGE_TRACKING == 1
64 struct dumperinfo di, *livedi;
65 struct diocskerneldump_arg kda;
71 error = priv_check(curthread, PRIV_KMEM_READ);
78 error = getvnode(curthread, fd, &cap_write_rights, &fp);
83 if ((fp->f_flag & FWRITE) == 0) {
88 /* Set up a new dumper. */
89 bzero(&di, sizeof(di));
90 di.dumper_start = vnode_dumper_start;
91 di.dumper = vnode_dump;
92 di.dumper_hdr = vnode_write_headers;
93 di.blocksize = PAGE_SIZE; /* Arbitrary. */
94 di.maxiosize = MAXDUMPPGS * PAGE_SIZE;
96 bzero(&kda, sizeof(kda));
97 kda.kda_compression = compression;
98 error = dumper_create(&di, "livedump", &kda, &livedi);
102 /* Only allow one livedump to proceed at a time. */
103 if (sx_try_xlock(&livedump_sx) == 0) {
104 dumper_destroy(livedi);
109 /* To be used by the callback functions. */
112 /* Lock the entire file range and vnode. */
113 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
114 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
116 EVENTHANDLER_INVOKE(livedumper_start, &error);
121 error = minidumpsys(livedi, true);
123 EVENTHANDLER_INVOKE(livedumper_finish);
126 vn_rangelock_unlock(vp, rl_cookie);
127 sx_xunlock(&livedump_sx);
128 dumper_destroy(livedi);
130 fdrop(fp, curthread);
134 #endif /* MINIDUMP_PAGE_TRACKING == 1 */
138 vnode_dumper_start(struct dumperinfo *di, void *key, uint32_t keysize)
141 /* Always begin with an offset of zero. */
144 KASSERT(keysize == 0, ("encryption not supported for livedumps"));
149 * Callback from dumpsys() to dump a chunk of memory.
152 * arg Opaque private pointer to vnode
153 * virtual Virtual address (where to read the data from)
154 * offset Offset from start of core file
162 vnode_dump(void *arg, void *virtual, off_t offset, size_t length)
169 ASSERT_VOP_LOCKED(vp, __func__);
171 EVENTHANDLER_INVOKE(livedumper_dump, virtual, offset, length, &error);
179 error = vn_rdwr(UIO_WRITE, vp, virtual, length, offset, UIO_SYSSPACE,
180 IO_NODELOCKED, curthread->td_ucred, NOCRED, NULL, curthread);
182 uprintf("%s: error writing livedump block at offset %jx: %d\n",
183 __func__, (uintmax_t)offset, error);
188 * Callback from dumpsys() to write out the dump header, placed at the end.
191 vnode_write_headers(struct dumperinfo *di, struct kerneldumpheader *kdh)
199 ASSERT_VOP_LOCKED(vp, __func__);
201 /* Compensate for compression/encryption adjustment of dumpoff. */
202 offset = roundup2(di->dumpoff, di->blocksize);
204 /* Write the kernel dump header to the end of the file. */
205 error = vn_rdwr(UIO_WRITE, vp, kdh, sizeof(*kdh), offset,
206 UIO_SYSSPACE, IO_NODELOCKED, curthread->td_ucred, NOCRED, NULL,
209 uprintf("%s: error writing livedump header: %d\n", __func__,